Re: retrieve command result

[Stephen Leake <stephen.a.leake.1@gsfc.nasa.gov>]

evangeli <evangeli@cnam.fr> writes:

> hi all
> 
> is it possible to retrieve the result of a command in a variable.
> i explain myself:
> 
> ------------------------------------------------------------------
> with GNAT.OS_Lib;
> with Ada.Strings.Unbounded;
> procedure Test is
> 	...
> 	my_string : Ada.Strings.Unbounded.unbounded_string;
> 	...
> begin
> 	...
> 	GNAT.OS_Lib.Spawn("ls", ...);
> 	-- I WOULD LIKE TO GET IN my_string THE RESULT OF THE ls COMMAND
> 	...
> end;
> ------------------------------------------------------------------
> 
> i am under linux with gnat 3.13p.

First, upgrade to 3.14p.

In general, you need to map the "standard output stream" of the
spawned program to a stream that you then read.

There is no Standard way to do this, and I see nothing in the GNAT
extensions for it either.

Linux has a spawn function that allows you to do this (sorry, I don't
know what it is called); find it in a Linux reference, import it into
Ada, and call it. Ideally, you should figure out how to use
Ada.Streams to provide the stream you read from.

-- 
-- Stephe